Engineering Siglec15/TGF-beta targeted bispecific antibodies that modulate the tumor microenvironment and enhances T-cell immunotherapy against pancreatic cancer

工程化 Siglec15/TGF-β 靶向双特异性抗体可调节肿瘤微环境并增强针对胰腺癌的 T 细胞免疫治疗

• 批准号: 10651442
• 负责人: Samuel Lai
• 金额: $ 21.49万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10651442
• 关键词: Abbreviations; Affinity; Agreement; Animals; Antibodies; Avidity; B-Lymphocytes; Binding; Bispecific Antibodies; Bite; C57BL/6 Mouse; CD3 Antigens; CD8-Positive T-Lymphocytes; CTLA4 gene; CXCL13 gene; Cancer Etiology; Cells; Cessation of life; Characteristics; Data; Disease; Dose; Drug Delivery Systems; Effectiveness; Engineering; Epithelial Cells; Fab domain; Goals; Growth; Human; Image; Immune; Immune Evasion; Immune checkpoint inhibitor; Immunocompetent; Immunoglobulin G; Immunoglobulin M; Immunosuppression; Immunosuppressive Agents; Immunotherapy; Infiltration; Lead; Leukocytes; Light; Macrophage; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of pancreas; Mammary Neoplasms; Measures; Mediating; Mesenchymal; Modeling; Molecular; Mus; Myeloid Cells; Myeloid-derived suppressor cells; Nature; Pancreas; Pancreatic Ductal Adenocarcinoma; Patients; Peripheral Blood Mononuclear Cell; Pilot Projects; Production; Publications; Regulatory T-Lymphocyte; Resistance; Signal Transduction; Stromal Cells; Suppressor-Effector T-Lymphocytes; Survival Rate; T cell response; T-Cell Activation; T-Cell Proliferation; T-Lymphocyte; Therapeutic; Toxic effect; Transforming Growth Factor beta; Tumor Cell Migration; Tumor Promotion; Tumor Suppression; Tumor-associated macrophages; Vascularization; Work; Xenograft Model; bi-specific T cell engager; bioprocess; chemotherapy; cytokine; design; effective therapy; improved; knock-down; luminescence; melanoma; monocyte; mortality; mouse model; nanomedicine; nuclear factors of activated T-cells; overexpression; pancreatic cancer cells; pancreatic cancer model; pancreatic cancer patients; pancreatic ductal adenocarcinoma cell; pancreatic neoplasm; programmed cell death ligand 1; response; safety assessment; subcutaneous; triple-negative invasive breast carcinoma; tumor; tumor growth; tumor microenvironment; tumor-immune system interactions

Pancreatic ductal adenocarcinoma (PDAC), which accounts for more than 90% of the pancreatic cancer cases, unfortunately has an average 5-year survival rate of less than 10%. To date, both chemotherapy and immunotherapy, including the checkpoint inhibitors like PD-L1, CTLA-4, has not been effective in treating PDAC. Although PDAC is infiltrated with leukocytes, they are mostly the suppressive types such as myeloid- derived suppressor cells, regulatory B cells, T regulatory cells and M2-macrophages, likely due to elevated levels of molecules such as TGF-β that suppresses T-cell activation. We have identified Siglec-15 (S15), which can directly inhibit NFKβ/NFAT signaling resulting in suppressed T-cell proliferation and cytokine production, as a critical immune suppressor in tumor microenvironment. Interestingly, S15 is broadly upregulated in various cancers, including triple negative breast cancers and PDAC, as well as tumor-associated macrophages, with no detectible expression in other healthy cells besides monocytes. Elevated expression of S15 is correlated with poor survival in PDAC patients. Importantly, Siglec15 is highly expressed in PDAC cells with low PD-L1, suggesting Siglec15 may be involved in immune evasion observed in PDL1-negative PDAC. Given the overexpression of S15 in PDAC, we hypothesized that a bispecific antibody (bsAb) that binds both S15 and an immune-suppressive cytokine (TGF-β) could result in greater bsAb accumulation in the tumor, and thus synergistically enhances T-cell activation for improved tumor suppression. We hypothesize that bispecific T-cell engagers (BiTE) that bind S15 and CD3 could likewise enhance T-cell immunotherapy against PDAC, including breaking down the stromal barrier. In pilot studies, our S15/TGF-β bsAb afforded much more effective tumor suppression than a cocktail of anti-S15 and anti-TGF-β Ab in mouse model of triple negative breast cancer. Likewise, S15/CD3 BiTE effectively suppressed pancreatic tumor in a xenograft model. Building off these promising findings, we seek to explore whether simultaneously modulation of the tumor immune microenvironment with improved T-cell targeting can lead to more effective therapy against PDAC. Towards this goal, we will engineer in Aim 1 a panel of bsAb that binds S15 while possessing different number of binding domains against TGF-β. We will evaluate whether the increased number of TGF-β binding domains further reduce immune suppression in the tumor leading to more effective therapy in an orthotopic pancreatic model in mice. In Aim 2, we will investigate whether the most potent S15/TGF-β bsAb from Aim 1 may synergistically enhance S15/CD3 BiTE therapy, both in an orthotopic human pancreatic cancer model in NSG mice infused with human PBMC and in a syngeneic orthotopic mice pancreatic cancer model. If successful, our work may lead to improved treatment options for management of PDAC, as well as advance an overall framework to enhance immunotherapy against different cancers.

胰腺导管腺癌（PDAC），占胰腺癌的90%以上 不幸的是，迄今为止，两种癌症病例的平均 5 年生存率均低于 10%。 免疫疗法，包括 PD-L1、CTLA-4 等检查点抑制剂，在治疗方面尚未有效 PDAC虽然有白细胞浸润，但大多是抑制型，如骨髓细胞。 衍生的抑制细胞、调节性 B 细胞、调节性 T 细胞和 M2 巨噬细胞，可能是由于 抑制 T 细胞活化的分子（如 TGF-β）水平。 我们已经鉴定出 Siglec-15 (S15)，它可以直接抑制 NFKβ/NFAT 信号传导，从而导致 抑制 T 细胞增殖和细胞因子产生，作为肿瘤的关键免疫抑制剂 微环境表明，S15 在各种癌症中广泛上调，包括三阴性乳腺癌。 癌症和 PDAC，以及肿瘤相关巨噬细胞，在其他健康细胞中没有检测到表达 除单核细胞外，S15 的表达升高与 PDAC 患者的生存率低相关。 重要的是，Siglec15 在 PD-L1 水平较低的 PDAC 细胞中高表达，表明 Siglec15 可能参与其中 在 PDL1 阴性 PDAC 中观察到的免疫逃避。 鉴于 PDAC 中 S15 的过度表达，我们寻求一种双特异性抗体 (bsAb) 结合 S15 和免疫抑制细胞因子 (TGF-β) 可能会导致双特异性抗体在 肿瘤，从而协同增强 T 细胞活化，从而改善肿瘤抑制。 结合 S15 和 CD3 的双特异性 T 细胞接合器 (BiTE) 同样可以增强 T 细胞免疫治疗 在试点研究中，我们的 S15/TGF-β bsAb 提供了对抗 PDAC 的能力。 在三重小鼠模型中，比抗 S15 和抗 TGF-β 抗体的混合物更有效地抑制肿瘤 同样，S15/CD3 BiTE 在异种移植模型中有效抑制了胰腺肿瘤。 基于这些有希望的发现，我们试图探索是否同时调节 具有改进的 T 细胞靶向的免疫肿瘤微环境可以带来更有效的治疗 为了实现这一目标，我们将在 Aim 1 中设计一组结合 S15 同时拥有不同的 bsAb。 我们将评估 TGF-β 结合域的数量是否增加。 该结构域进一步减少肿瘤中的免疫抑制，从而在原位治疗中实现更有效的治疗 在小鼠胰腺模型中，我们将研究 Aim 1 中最有效的 S15/TGF-β bsAb。 可能协同增强 S15/CD3 BiTE 治疗，两者均在原位人类胰腺癌模型中 NSG 小鼠注入人 PBMC 并用于同基因原位小鼠胰腺癌模型。 如果成功，我们的工作可能会改善 PDAC 管理的治疗方案，并推进 增强针对不同癌症的免疫治疗的总体框架。